The Kaplan verbal workbook
has a wider variety of material to practice from, as opposed to the general Kaplan
workbook with CD. As well, if I were you, I would definetly look into the Kaplan Math workbook
for the GMAT & GRE it's an excellent guide.
It just so happens that I have both of those for sale
....They are in mint condition ......ie. never used....If you're interested take a look under the Buy & Sell section of the Forum....or you can contact me at email@example.com
.......Please put GMAT materials as the subject line as I get many e-mails daily.